Recently, with the growing public interest in beauty, people take an increasing interest in tooth whitening. Selections for tooth whitening include toothpastes, mouth rinses, chewing gums, indoor whitening, and tooth whitening solutions using the most common trays available from stores or dentists. A tooth whitening solution generally contains an active ingredient that bleaches the tooth, such as hydrogen peroxide.
Hydrogen peroxide dissolves water, ethanol, and ether well, and as some hydrogen ions dissolute in an aqueous solution, it is a weak acid. Hydrogen peroxide is an unstable material, and activity continues to reduce over time. Thus, general tooth whitening products use a hydrogen peroxide stabilizer that maintains the activity of hydrogen peroxide to prevent the activity reduction of hydrogen peroxide during distribution.
However, when the tooth whitening product is used in real situations, the stabilizer acts as a hindrance factor to activity of hydrogen peroxide, and to solve the problem, a catalyst is used to induce rapid activity of hydrogen peroxide. The catalyst includes a substance that enhances a tooth whitening effect by its reaction with peroxide to generate perhydroxy radicals, and a metal catalyst that promotes the decomposition of peroxide.
On the other hand, when peroxide gets in abrupt touch with the gum, tooth sensitivity and gingival irritation often occurs due to the abrupt action of the whitening ingredient activator for inducing rapid activity of peroxide (e.g., hydrogen peroxide) as mentioned above.
Accordingly, approaches are needed to allow a sufficient tooth whitening effect of peroxide and at the same time, minimize irritation transferred to the tooth and the gum, while maintaining the stability of peroxide during distribution.